In both hETA-expressing CHO-K1 cells treated with 10 nM ET-1 and HT-29 colorectal cancer cells treated with the same concentration of ET-1, the scAb AG8 inhibited the ET-1-induced increase in the intracellular Ca2+ level, as evidenced by the IC50 values (56 nM in CHO-K1 cells and 51 nM in HT-29 cells). Here, EDN1 is linked to colorectal cancer.